Defensive publication



DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at the request of the applicant or owner in accordance with the Notice of Apr. 11, 1968, 849 O.G. 1221. Identification is by serial number of the application and the heading indicates the number of pages or specification, including claims, and of sheets of drawing contained in the application as originally filed, The die of this application is available to the public for inspection; reproduction may be purchased for 30 cents per sheet. 7

Applications published under the Defensive Publication Program have not been examined as to the merits or alleged invention. The Patent Oflice makes no assertion as to the novelty oi. the disclosed subject matter.

PUBLISHED OCTOBER 28, 1969 818,419 REVERSAL SYSTEM CONTAINING A PYRIDYL- IDENE RHODANINE DYE Robert C. Taber, Kodak Park Division, Rochester, N.Y. 14650 Filed Apr. 22, 1969. Published Oct. 28, 1969 Int. Cl. G03c 5/50, 5/30, 1/48 US. CI. 96-59 No Drawing. 9 Pages Specification Processing an exposed photographic element in a reversal system employing chemical development and physical development in one element in the presence of a pyridylidene rhodanine dye provides desired lower positive minimum density and improved image tone. A pyridylidene rhodanine dye, such as 3-ethyl-5[(l-(4-sulfobutyl)-4(1H)-pyridylidene)] rhodanine sodium salt, 3-ethyl- 5-(1-ethyl-4( lI-l)pyridylidene)rhodanine and/or 3-ethyl- 5-(1-beta-hydroxyethyl-4(1H)-pyridylidene) rhodanine in a monobath and/or in a photographic element containing a photographic silver halide emulsion and development nuclei provides the described improved properties. 

